On 4/7/24 2:13 AM, Oleg Nesterov wrote:
Muhammad,
I am sorry, but... are you aware that this patch was applied over a year ago, and then this code was updated to use the ksft_API?
Sorry, didn't realized this is already applied. So this patch is already applied and it has already been made compliant.
Thanks
Oleg.
On 04/07, Muhammad Usama Anjum wrote:
On 3/16/23 5:30 PM, Marco Elver wrote:
From: Dmitry Vyukov dvyukov@google.com
Test that POSIX timers using CLOCK_PROCESS_CPUTIME_ID eventually deliver a signal to all running threads. This effectively tests that the kernel doesn't prefer any one thread (or subset of threads) for signal delivery.
Signed-off-by: Dmitry Vyukov dvyukov@google.com Signed-off-by: Marco Elver elver@google.com
v6:
- Update wording on what the test aims to test.
- Fix formatting per checkpatch.pl.
tools/testing/selftests/timers/posix_timers.c | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+)
diff --git a/tools/testing/selftests/timers/posix_timers.c b/tools/testing/selftests/timers/posix_timers.c index 0ba500056e63..8a17c0e8d82b 100644 --- a/tools/testing/selftests/timers/posix_timers.c +++ b/tools/testing/selftests/timers/posix_timers.c @@ -188,6 +188,80 @@ static int check_timer_create(int which) return 0; } +int remain; +__thread int got_signal;
+static void *distribution_thread(void *arg) +{
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
- return NULL;
+}
+static void distribution_handler(int nr) +{
- if (!__atomic_exchange_n(&got_signal, 1, __ATOMIC_RELAXED))
__atomic_fetch_sub(&remain, 1, __ATOMIC_RELAXED);+}
+/*
- Test that all running threads _eventually_ receive CLOCK_PROCESS_CPUTIME_ID
- timer signals. This primarily tests that the kernel does not favour any one.
- */
+static int check_timer_distribution(void) +{
- int err, i;
- timer_t id;
- const int nthreads = 10;
- pthread_t threads[nthreads];
- struct itimerspec val = {
.it_value.tv_sec = 0,.it_value.tv_nsec = 1000 * 1000,.it_interval.tv_sec = 0,.it_interval.tv_nsec = 1000 * 1000,- };
- printf("Check timer_create() per process signal distribution... ");
Use APIs from kselftest.h. Use ksft_print_msg() here.
- fflush(stdout);
- remain = nthreads + 1; /* worker threads + this thread */
- signal(SIGALRM, distribution_handler);
- err = timer_create(CLOCK_PROCESS_CPUTIME_ID, NULL, &id);
- if (err < 0) {
perror("Can't create timer\n");ksft_perror() here
return -1;- }
- err = timer_settime(id, 0, &val, NULL);
- if (err < 0) {
perror("Can't set timer\n");return -1;- }
- for (i = 0; i < nthreads; i++) {
if (pthread_create(&threads[i], NULL, distribution_thread, NULL)) {perror("Can't create thread\n");return -1;}- }
- /* Wait for all threads to receive the signal. */
- while (__atomic_load_n(&remain, __ATOMIC_RELAXED));
- for (i = 0; i < nthreads; i++) {
if (pthread_join(threads[i], NULL)) {perror("Can't join thread\n");return -1;}- }
- if (timer_delete(id)) {
perror("Can't delete timer\n");return -1;- }
- printf("[OK]\n");
ksft_test_result or _pass variant as needed?
- return 0;
+}
int main(int argc, char **argv) { printf("Testing posix timers. False negative may happen on CPU execution \n"); @@ -217,5 +291,8 @@ int main(int argc, char **argv) if (check_timer_create(CLOCK_PROCESS_CPUTIME_ID) < 0) return ksft_exit_fail();
- if (check_timer_distribution() < 0)
return ksft_exit_fail();- return ksft_exit_pass();
}
-- BR, Muhammad Usama Anjum